Xylan phenyl carbonate (XPC) derivatives were prepared and characterized comprehensively. By conversion of xylan with phenyl chloroformate either in dipolar aprotic solvents with LiCl or in an ionic liquid, XPC with degrees of substitution (DS) of up to 2.0, i.e., fully functionalized derivatives, could be obtained. The synthesis was studied with respect to the influence of different reaction parameters. It was found that the reaction medium as well as the type of starting xylan strongly affected the efficiency of the derivatization. The derivatives obtained were characterized by FT-IR- and NMR spectroscopy. Surprisingly, it was found that C-3 is the most reactive position in this particular reaction while substitution in position C-2 only occurred if the neighboring position C-3 already carried a phenyl carbonate group. XPC were found to form spherical nanoparticles (NP) of well-defined shape with diameters around 158 nm. These materials possess unique potential as activated NP for advanced applications.
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http://dx.doi.org/10.1016/j.carbpol.2018.03.083 | DOI Listing |
Int J Biol Macromol
August 2024
College of Material Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China; National Forestry and Grassland Administration Key Laboratory of Plant Fiber Functional Materials, Fuzhou 350108, PR China. Electronic address:
Biomass recalcitrance, a key challenge in biomass utilization, is closely linked to the architectural composition and cross-linkages of molecules within cell walls. With three bamboo species investigated, this study aims to elucidate the inherent molecular-scale structural differences between bamboo fibers and parenchyma cells through a systematic chemical extraction and structural characterization of isolated hemicelluloses, lignin, and lignin-carbohydrate complexes (LCC). We observed that parenchyma cells exhibit superior alkaline extractability compared to fibers.
View Article and Find Full Text PDFJ Agric Food Chem
May 2024
Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, School of Light Industrial and Food Engineering, Guangxi University, Nanning 530004, P. R. China.
Bamboo is a promising biomass resource. However, the complex multilayered structure and chemical composition of bamboo cell walls create a unique anti-depolymerization barrier, which increases the difficulty of separation and utilization of bamboo. In this study, the relationship between the connections of lignin-carbohydrate complexes (LCCs) within bamboo cell walls and their multilayered structural compositions was investigated.
View Article and Find Full Text PDFCarbohydr Polym
June 2024
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China. Electronic address:
To investigate the interplay between substrate structure and enzymatic hydrolysis (EH) efficiency, poplar was pretreated with acidic sodium-chlorite (ASC), 3 % sodium-hydroxide (3-SH), and 3 % sulfuric acid (3-SA), resulting in different glucose yields of 94.10 %, 74.35 %, and 24.
View Article and Find Full Text PDFCarbohydr Polym
April 2024
Friedrich Schiller University Jena, Institute for Organic Chemistry and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Humboldtstraße 10, D-07743 Jena, Germany. Electronic address:
A simple synthesis of amino polysaccharides (PS) could be developed. Phenyl carbonates (PC) of xylan, dextran, and cellulose were easily transferred into PS carbazates by conversion with hydrazine hydrate. The degree of substitution could be adjusted by varying the molar ratio of hydrazine to PS repeating unit, enabling the preparation of both pure PS carbazates and derivatives with bifunctional reactivity containing the reactive PC and the amino group of the carbazate moiety.
View Article and Find Full Text PDFChembiochem
March 2024
Surflay Nanotec GmbH, 12489, Berlin, Germany.
An efficient and easy-to-use approach is presented for obtaining biocompatible polysaccharide-based nanoparticles (NP) that can act as tumor-specific drug delivery agents. Two antibodies are directly immobilized onto reactive xylan phenyl carbonate (XPC) NP; namely Cetuximab (CTX) that binds to human epidermal growth factor receptor (EGFR) and Atezolizumab (ATZ) that binds to programmed death-ligand 1 (PD-L1). High coupling efficiency (up to 100 %) are achieved without any pre-activation and no aggregation occurs during antibody immobilization.
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